Thermal safety device for aerosol containers



United States Patent O 3,241,713 THERMAL SAFETY DEVICE FOR AEROSOL CONTAINERS Clarence Clapp, Montebello, and Robert J. Winkler, Granada Hills, Calif., assignors to Western Filling Corporation, Los Angeles, Calif., a corporation of California Filed Apr. 20, 1964, Ser. No. 361,167 6 Claims. (Cl. 222) This invention has to do with the prevention of disruption of gas pressurized aerosol containers as a consequence of excessive pressure development occasioned by overheating, and has for its general object to provide simple and economical thermally responsive means operable to depressure the container by gas release. g

Commonly such containers have top dispensing valve heads operable to open the valves proper either by lateral tilting or straight down displacement of the heads, to release the container contents. As packaged, such products have removable inverted cup-shaped caps applied to top areas of the containers about the valve heads. Particularly in the case of the more highly pressurized aerosols, their containers are subject to rupture when exposed to abnormally high temperatures because of the consequent gas pressure increase and practical limitations upon the coutailner wall strengths.

Our general object is to provide a simple, low cost and reliable safety device that will automatically act to depressurize the container in response to unsafe temperatures in excess of about 130 F. Particularly contemplated are such devices employing springs releasable from normally retracted to projected conditions or positions to 'cause gas release either by actuation of the dispensing valve or by penetration of the container itself.

Among our objects of primary importance is to restrain the spring release in its depressurizing action by a low temperature melting or softening material, the normal holding capability of which is overcome by the spring tension when a predetermined temperature is reached. As will appear we utilize preferably for such retaining means a suitable eutectic alloy, e.g. at least partially of lead, tin and bismuth, or of other composition Well known, which melts or softens sufiiciently to release the spring when heated to a predetermined temperature which as indicated, usually will be above 130 F.

As will appear, the invention contemplates provision of such safety devices within and mounted to the container cap or more directly to the container itself, and in either instance, types of spring urged thermally responsive devices operable to actuate the valve or to puncture the container.

The above as Well as various specific features and objects of the invention, as well as a number of illustrative embodiments of the invention will be more fully understood from the following description of the accompanying drawings, in which:

FIG. 1 is a view showing one cap-contained embodiment of the invention, the cap appearing in vertical section;

FIG. 2 is a fragmentary enlarged section taken on line I 2 2 of FIG. 1;

FIG. 3 is a view similar to FIG. 1 illustrating a similar variation of the invention;

FIG. 4 is a view similar to FIG, 1 illustrating a cap mounted form of the invention which effects pressure release by puncturing the container;

FIG. 4a is a fragmentary enlargement of the FIG. 4 release device;

FIG. 5 illustrates another embodiment of the invention similar to FIG. 4 in which the container puncturing device is mounted independently of the cap;

3,241,713 Patented Mar. 22, 1966 ice FIG. 6 is a section on line 66 of FIG. 5; and

FIG. 7 is a view similar to FIG. 5 showing a similarly mounted thermal device adapted to actuate the aerosol valve.

In the various views we show a conventional aerosol container 10, the top configuration of which comprises a cup 11 fitting the container head at the bead seal 12, the cup mounting a valve 13 of the lateral rocking type shown in FIG. 1, or of the straight push down type 14 appearing in FIGS. 3 to 5. For certain usages, as in sealant pressurizing of automobile tires, the valve may be designed or adapted for attachment to a tire valve stem. In FIG. 1 the valve head assembly is shown to include an adapter 13a for such purposes. The valves are designated by their dispensing heads and are of conventional types extending down through the cups 11 into the containers to be actuable to dispense the aerosol by lateral or axial displacement of the valve, as the case may be. The valves are shown to be contained within inverted cup-shaped caps 15 applied to the container about the bead 12 and containing openings as at 16 or 17 to release the aerosol in the event of valve actuation or container puncture by any of the thermally responsive devices now to be described.

Referring now to FIG. 1, the thermally responsive device generally indicated at 18 comprises a leaf spring 19 of bifurcated configuration, one arm 20 of which is suitably mounted to the cap as by retention within recesses 21 molded into the cap, see FIG. 2. Inner arm 22 of the spring extends upwardly adjacent the valve head 13 and opposite an inwardly turned terminal 20a of the spring arm 20. The spring arms are releasably retained in their illustrated positions by a pair of clip pieces 23 extending through openings 24 and 25 in the spring arms, the outer terminals of the clip pieces embracing and being held apart by a body 26 of low melting temperature alloy. In the FIG. 2 configuration the inner clip terminals 27 prevent release of the tensioned spring arm 22 from its normal connection with the spring terminal 20a. Upon being heated to predetermined temperature, as by exposure of the aerosol package to temperatures above F., the low temperature alloy 26 melts or softens sufliciently to release the clip retention of the spring arm 22 by collapsing together of the pieces 23, so that upon release, the arm 22 engages against the valve 13 with sufiicient thrust and extent of travel to open the valve and thereby depressurize the container.

The FIG. 3 embodiment is similar except that here the spring 27 mounted to the cap and having its upper terminals releasably retained at 28 as in FIG. 1, has at 29 a double band configuration to overlie the valve head 14 so that upon release of the spring arm 30, the latter presses down upon and opens the valve.

The FIG. 4 form of the invent-ion also is cap mounted but is designed for pressure release by puncture of the container itself, and specifically the bottom wall of the cup 11. Here the temperature responsive device 30 comprises a tube 31 molded integrally with the cap and containing a tubular puncture needle 32 given guide support at 33 and carrying a flange 34 against which coil spring 35 bears in the illustrated compressed condition of the spring, Normally the needle is maintained in elevated position by a latch arm extending toward opening 36 in the tube 31, the inner end of the latch engaging upwardly against the tapered rod flange 34. Normally the needle is retained in its upper position against the thrust of spring 35 by a piece of low melting alloy 37 inserted at the inside of the outer arm of the latch. Upon melting of the alloy the latch is freed to displace outwardly through the opening 36 sulficiently to disengage the flange 34 and free the needle for thrusting by the spring through the cup 11, thereby re leasing the container gas through the needle.

FIGS. 5 and 6 illustrate a variational form in which the temperature responsive device 38 also is mounted within the cap but independently thereof in being supported directly by the container, and specifically within the cup 11. Here the device is supported by a pedestal 40 having arms 41 provided with bottom flanges 42 which snap into retained engagement with the cup 11. The arms 40 are formed integrally with a bridge portion 43, the upper end of which is turned inwardly at 44. As illustrated, the arms 40 extend angularly to mount a puncture needle 45 in offset relation to the valve 14. Normally the needle 45 is maintained in elevated position against the resistance of a coil spring 46 bearing upwardly against abutment 47 and having its lower end bearing against the needle flange 48, by a thermally responsive release at the top of the needle. The latter is shown to comprise a pair of flexible wings 50 attached to the upper end of the needle above its extension through the turned support 44, and confining between them the eutectic alloy 51. Upon fusion of the latter, the thrust of spring 46 forces together the flexible wings 50 so that the latter are pulled down through the support 44 to release the needle for penetration of the cup 11 by the spring thrust.

The final form of the invention shown in FIG. 7 corresponds in all respects to the structure of FIGS. 5 and 6 in that the thermally responsive device is mounted by similar pedestal 52 and comprises an elongated or rod element 53 downwardly displaceable by coil spring 54 when released by the eutectic holding means 55. Here, instead of being a puncture needle, the rod 53 carries an arm 56 normally overlying the valve 14 and which, upon melting of the eutectic alloy and release of the rod, engages downwardly against the valve to open it for discharge of the aerosol.

We claim:

1. The combination comprising a gas pressurized aerosol container having a top dispensing valve, container depressurizing means carried by the container and including a spring biased means releasable from a retracted spring compressed position to a projected position to effect escape of gas from the container, and means retaining said spring biased means in its retracted position at normal temperatures and fusible at temperatures above about 130 F. to release the spring biased means, said depressurizing means being operable to engage and actuate the valve,

2. The combination comprising a gas pressurized aerosol container having a top displaceable dispensing valve head, a removable inverted cup-shaped cap on the container, depressurizing means including a spring within the cap biasing means releasable from a retracted spring compressed position to a projected position to effect escape of gas from the container, and means retaining said spring biased means in its retracted position at normal temperatures and fusible at temperatures above about 130 F. to release the spring biased means, said spring being mounted to the top wall of the container independently of the cap.

3. The combination comprising a gas pressurized aerosol container having a top displaceable dispensing valve head, a removable inverted cup-shaped cap on the container, depressurizing means including a spring within the cap biasing means releasable from a retracted spring compressed position to a projected position to effect escape of gas from the container, and means retaining said spring biased means in its retracted position at normal temperatures and fusible at temperatures above about F. to release the spring biased means, said depressurizing means upon release of the spring being operable to displace the valve head.

4. The combination comprising a gas pressurized aerosol container h-aving a top displaceable dispensing valve head, a removable inverted cup-shaped cap on the container, depressurizing means including a spring within the cap biasing means releasable from a retracted spring compressed position to a projected position to effect escape of gas from the container, and means retaining said spring biased means in its retracted position at normal temperatures and fusible at temperatures above about 130 F. to release the spring biased means, said spring being of bifurcated form mounted to the cap and being operable to displace the valve head laterally.

5. The combination comprising a gas pressurized aerosol container having .a top displaceable dispensing valve head, a removable inverted cup-shaped cap on the container, depressurizing means including a spring within the cap biasing means releasable from a retracted spring compressed position to a projected position to effect escape of gas from the container, and means retaining said spring biased means in its retracted position at normal temperatures and fusible at temperatures above about 130 F. to release the spring biased means, said spring being of bifurcated form mounted to the cap and being operable to displace the valve axially of the container.

6. The combination comprising an aerosol container cap applicable to the top of the container about a displaceable dispensing valve, and container depressurizing means carried by the cap and including a spring biased means releasable from a retracted spring compressed position to a projected position to effect gas escape from the container, and means maintaining the spring biased means in its retracted position at normal temperatures and fusible at temperatures above about 130 F. to release the spring biased means, said depressurizing means being operable to displace said valve by release of the spring.

References Cited by the Examiner UNITED STATES PATENTS 2,822,961 2/1958 Seaquist 222396 X 3,008,479 11/1961 Mancusi 222-5 X LOUIS J. DEMBO, Primary Examiner.

RAPHAEL M. LUPO, Examiner.

N, L. STACK, Assistant Examiner. 

1. THE COMBINATION COMPRISING A GAS PRESSURIZED AEROSOL CONTAINER HAVING A TOP DISPENSING VALVE, CONTAINER DEPRESSURIZING MEANS CARRIED BY THE CONTAINER AND INCLUDING A SPRING BIASED MEANS RELEASABLE FROM A RETRACTED SPRING COMPRESED POSITION TO A PROJECTED POSITION TO EFFECT ESCAPE OF GAS FROM THE CONTAINER, AND MEANS RETAINING SAID SPRING BIASED MEANS IN ITS RETRACTED POSITION AT NORMAL TEMPERATURES AND FUSIBLE AT TEMPERATURES ABOVE ABOUT 130* F. TO RELEASE THE SPRING BIASED MEANS, SAID DEPRESSURIZING MEANS BEING OPERABLE TO ENGAGE AND ACTUATE THE VALVE. 